The demand for higher data rates and the growth of mobile broadband services continues to push the need to advance HSPA (high speed packet access) technology.
For example, 3GPP HSDPA (high speed downlink packet access) with Multiple Input Multiple Output (MIMO) transmission has been defined in 3GPP Release 7 to enable a 28 Mbps data rate. The combination of MIMO and 64QAM provides a 42 Mbps in Release 8 and in Release 9, dual cell HSDPA and MIMO and 64 QAM are defined to enable 84 Mbps. Release 10 will be approaching even higher data rates with 168 Mbps being achievable by having four carriers and MIMO. With the increased data rates, the buffer sizes in the devices (user equipment or UEs) also increase when the delay is unchanged.
As the data rates keep increasing in the future, the resulting buffers will grow even more and earlier solutions employed in HSPA will not be able to reduce the resulting latency/delay.
Therefore a solution is required for HSPA networks, which increases efficiency and reduces delay when the data rates, and therefore the size of the buffers, increase.